It may well be psychological. You've mentioned before that you can be a worrier, and worrying that you won't cum can tend to hold it back. Also I find that stress and tiredness/lack of sleep keep me from ejaculating, and in some previous posts you seemed to be stressed and losing sleep because of work.

Me and my gf often have what maybe you'd call real relaxed sex where I'm lying on my back and she's sorta sitting on me with me inside her, and we just have a nice relaxed conversation. We mnigt talk about lots of stuff, just maybe rocking back and forth a little bit and enjoying the feeling and te closeness. I guess what I'm saying is that we're not at all concentrating on the sex any more thn if we were in a park walking and talking and holding hands. We would not be concentrating on the "holding hands" part.Then after a while, either me or both of us will start getting so sensitive that we both want to start going faster and harder, and then we let it finish. But we don't rush it. we might take an hour sometimes just relaxing anddoing it this way. So my advice is to just put your bodies together and then sorta forget about what's going on "down there", and just enjoy it! (See what happens!)